CN109313006B

CN109313006B - System, method and object for high accuracy magnetic position sensing

Info

Publication number: CN109313006B
Application number: CN201680085804.3A
Authority: CN
Inventors: R·泰特罗特; L·博米耶; C·赫伯特; S·利弗琳
Original assignee: Kongsberg Inc
Current assignee: Kongsberg Inc
Priority date: 2016-05-17
Filing date: 2016-05-17
Publication date: 2021-02-02
Anticipated expiration: 2036-05-17
Also published as: EP3458805B1; US20190178683A1; CN109313006A; US11821763B2; EP3458805A4; WO2017199063A1; EP3458805A1; US20210278251A1

Abstract

Systems and methods for determining location are provided. The object generates a magnetic field having a first vector component, a second vector component, and a third vector component that are orthogonal to each other. The sensor measures a magnitude of each of the first, second and third vector components when the object is within the range of positions. A controller is connected to the sensor and determines a relative position of the object over an undetermined period of a plurality of periods based on the magnitude of the first vector component and the magnitude of the second vector component. The controller determines a period of the plurality of periods in which the object is located based on the magnitude of the third vector component. The controller determines an absolute position of the object based on the relative position of the object and the period in which the object is located.

Description

System, method and object for high accuracy magnetic position sensing

Background

Technical Field

The present invention relates to a system and method for high accuracy magnetic position sensing of an object, and more particularly, where magnetic position sensing is achieved by measuring three vector components of a magnetic field generated by the object.

Background

Magnetic position sensing technology is becoming an increasingly popular form of detection in various systems. However, conventional magnetic position sensing methods determine position using only two vector components of the magnetic field of the sensed object. For example, in automotive applications such as clutch position measurement systems and transmission position sensing systems, conventional methods of sensing position using only two vector components of a magnetic field are not sufficient to provide the high accuracy and precision measurements required by modern time-sensitive and position-sensitive automotive control systems. Another exemplary application is a brushless DC motor control system, where the magnetic elements of the rotor of the brushless DC motor need to be measured for tuning and efficient operation of the motor. Conventional magnetic position sensing methods measure only two vector components of the magnetic field of the sensed object and substantially determine the position of the object thereon. Thus, conventional methods are not accurate and precise enough to allow reliable operation of innovative position sensitive control systems that rely on highly accurate position determination.

Disclosure of Invention

Embodiments of a system for determining a location are provided. The system includes an object. The object is configured to generate a magnetic field having a first vector component, a second vector component, and a third vector component. The first, second and third vector components are orthogonal to each other. The sensor is configured to measure a magnitude of each of the first, second, and third vector components when the object is within the range of positions. The controller is connected to the sensor. The controller is configured to determine a relative position of the object within an undetermined period of the plurality of periods based on the magnitude of the first vector component and the magnitude of the second vector component. The controller is configured to determine a period of the plurality of periods in which the object is located based on the magnitude of the third vector component. The controller is configured to determine an absolute position of the object based on the relative position of the object and a period in which the object is located.

A method of operating a system for determining a location is provided. The system includes an object, a sensor, and a controller connected to the sensor. The object is configured to move within a range of positions. The object is further configured to provide a magnetic field having a first vector component, a second vector component, and a third vector component. The first, second and third vector components are orthogonal to each other. The object moves within the range of positions. The sensor measures a magnitude of each of the first, second, and third vector components when the object is within the range of positions. The controller determines a relative position of the object within an undetermined period of the plurality of periods based on the magnitude of the first vector component and the magnitude of the second vector component. The controller determines a period in the plurality of periods in which the object is located based on the magnitude of the third vector component. The controller determines an absolute position of the object based on the relative position of the object and the period in which the object is located.

Embodiments of an object for use in position sensing are also provided. The object has a length. The object is configured to move linearly within a range of positions. The object is configured to generate a magnetic field having a first vector component, a second vector component, and a third vector component. The first, second and third vector components are orthogonal to each other. The magnitude of the first vector component and the magnitude of the second vector component each vary periodically along the length of the object. The magnitude of the third vector component is unique for each position of the sensor along the length of the object.

The system, method and object advantageously provide a high accuracy determination of the object position by three-dimensional magnetic sensing. By determining the position of the object based on the three-dimensional magnitude of the magnetic field generated by the object, the position of the object can be determined with extremely high accuracy and precision. This allows the system and method to be implemented in innovative position sensitive control systems that rely on high accuracy position sensing, such as transmission control modules of automotive automatic mechanical transmissions that rely on high accuracy position determination of the clutch, and high efficiency and high accuracy brushless DC motor control systems that rely on high accuracy position determination of the magnetic rotor.

Drawings

Advantages of the invention will be readily appreciated and better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

FIG. 1 is a perspective view of one embodiment of a system for determining the position of an object using a sensor located at a fixed distance from the object and a controller in communication with the sensor.

FIG. 2 is a perspective view of another embodiment of a system for determining position in which an object includes a plurality of magnets.

FIG. 3 is a layout of one embodiment of an object for use in position sensing.

FIG. 4 is a graph illustrating magnitudes of first, second, and third vector components of an object acquired by a sensor according to an example.

Fig. 5 is a graph showing the relationship of the first and second vector components to the relative position of the object and the relationship of the third vector component to the period in which the object is located within a plurality of periods according to one example.

FIG. 6 is a perspective view of yet another embodiment of a system for determining position in which an object is secured to a clutch positioning member of an automatic mechanical transmission.

FIG. 7 is a flow chart of an embodiment of a method of determining location.

Detailed Description

Referring to the drawings, wherein like numerals indicate like or corresponding parts throughout the several views, aspects of a system 10 and method 30 for sensing a position of an object 12 are provided.

I. Description of the System

Fig. 1 illustrates an embodiment of a system 10. The system 10 includes an object 12, a sensor 14, and a controller 16. The object 12 is configured to generate a magnetic field H. The magnetic field H has a first vector component V1, a second vector component V2, and a third vector component V3. The first, second and third vector components V1, V2, V3 are orthogonal to each other.

Object 12 may have several configurations. In fig. 1, object 12 is substantially cylindrical and has a first end 18 and a second end 20. Each of the first, second, and third vector components V1, V2, V3 has a direction and a magnitude. The direction of the first vector component V1 extends radially from object 12 in the direction of sensor 14. The direction of second vector component V2 extends longitudinally through object 12, orthogonal to first vector component V1. The direction of the third vector component V3 extends radially from the object 12, orthogonal to both the first and second vector components V1, V2. The object 12 may be of any shape suitable for generating a magnetic field H. Object 12 may have a configuration different from that specifically described herein.

In fig. 1, object 12 is a single magnet configured to generate a magnetic field H. In fig. 2, object 12 includes a plurality of magnets 26 configured to together generate a magnetic field H. In some embodiments, the magnet 26 is a permanent magnet. In other embodiments, the magnet 26 is an electromagnet.

The sensor 14 is a magnetic field sensor configured to measure the magnitude of each of the first, second and third vector components V1, V2, V3 of the magnetic field H when the object 12 is within the range of the location 22. The magnitude of each of the first, second and third vector components V1, V2, V3 may be measured in terms of magnetic flux density or magnetic field strength. Although the letter "H" is used herein to refer to the magnetic field H, to the strength of the magnetic field H in amperes per meter, the magnetic field H may also represent the lorentz force it exerts on the moving charge, i.e., "B," or any other suitable method of representing the magnetic field generated by the magnetized material.

The range of positions 22 is defined such that when object 12 moves within the range of positions 22, object 12 moves along a single axis such that sensor 14 is located between first end 18 and second end 20 and sensor 14 is maintained at a fixed distance 24 from object 12. Object 12 may be moved along a single axis via a predetermined path. In some embodiments, the range of the location 22 is shorter due to edge effects of the magnetic field H. Edge effects affect the measurement of the magnetic field H such that it is undesirable to measure the magnitudes of the first, second and third vector components V1, V2, V3 near the first end 18 or the second end 20 of the object 12.

The sensor 14 is configured to measure the magnitude of each of the first, second and third vector components V1, V2, V3 of the magnetic field H substantially simultaneously. The sensor 14 may be any type of sensor capable of measuring the magnitude of each of the first, second and third vector components V1, V2, V3 of the magnetic field H, such as, but not limited to, a rotating coil, a hall effect, a magneto-resistance, a flux gate, a superconducting quantum interference device, or a spin-exchange-free relaxed atomic magnetometer. The sensors 14 may have configurations other than those specifically described herein.

The controller 16 is in communication with the sensor 14. Controller 16 performs many of the high accuracy position determination steps of method 40. The controller 16 receives the magnitudes of the first, second and third vector components V1, V2, V3 of the magnetic field H from the sensor 14. The controller 16 may be a microcontroller, a state machine, a field programmable gate array, a CPU or any other device suitable for receiving and analyzing the magnitudes of the first, second and third vector components V1, V2, V3 from the sensor 14.

Referring to FIG. 4, object 12 is configured such that the magnitude of first vector component V1 and the magnitude of second vector component V2 measured by sensor 14 are both periodic functions as object 12 moves across the range of positions 22. In one embodiment, the amplitude of the first vector component V1 and the amplitude of the second vector component V2 are both sinusoidal. The amplitudes of the first and second vector components V1, V2 measured at any position within the range of position 22 have a phase difference Δ. In another embodiment, the magnitude of the first vector component V1 is substantially similar to a cosine wave and the magnitude of the second vector component V2 is substantially similar to a sine wave.

Object 12 is configured such that the magnitude of third vector component V3 has a unique value for each possible position of sensor 14 relative to object 12 as object 12 moves across the range of positions 22. In some embodiments, the magnitude of the third vector component V3 is a monotonic function. In one example, the magnitude of the third vector component V3 continuously increases as object 12 moves across the range of positions 22. In another example, the magnitude of the third vector component V3 continuously decreases as the object 12 moves across the range of positions 22.

Fig. 4 is a graph showing the magnitude of the first, second and third vector components V1, V2, V3 of an exemplary embodiment of the present invention. The graph has a horizontal field axis and a vertical field axis. The position axis corresponds to the position of object 12 within range of position 22. The leftmost value on the position axis corresponds to object 12 being located within position 22 such that sensor 14 is closest to first end 18 of object 12. Increasing the value of the position axis, i.e., further to the right of the position axis, corresponds to object 12 being positioned such that sensor 14 is closer to second end 20 of object 12. The rightmost value on the position axis corresponds to object 12 being located within a range of positions 22 such that sensor 14 is closest to second end 20 of object 12.

The magnetic field axis corresponds to the magnitude of the first, second and third vector components V1, V2, V3 measured by the sensor 14 and communicated to the controller 16 at each position along the horizontal axis. In FIG. 4, the amplitudes of the first vector component V1 and the second vector component V2 are sinusoidal with a phase difference Δ of about π/2 radians, i.e., 90 degrees. The magnitudes of first vector component V1 and second vector component V2 are periodic functions related to the position of object 12 within range of position 22. The magnitude of third vector component V3 is a monotonic function related to the position of object 12 within range of position 22. In FIG. 4, the magnitude of third vector component V3 continuously increases as object 12 moves across the range of positions 22 such that sensor 14 measures the magnitude of third vector component V3 from near first end 18 of object 12 to near second end 20 of object 12.

With continued reference to FIG. 4, the position of object 12 at each cycle of the magnitude of each of first vector component V1 and second vector component V2 defines each cycle of the plurality of

cycles

28a, 28b, 28c, 28d, 28 e. In the embodiment of the invention shown in fig. 4, the plurality of

cycles

28a, 28b, 28c, 28d, 28e comprises five cycles. The number of cycles depends on the magnetic field H and therefore on the configuration of the object 12. It should be understood that object 12 may be configured in a variety of ways, and that plurality of

cycles

28a, 28b, 28c, 28d, 28e may include any number of cycles.

FIG. 3 illustrates one embodiment of object 12 including a plurality of magnets 26. The number of cycles included in the plurality of

cycles

28a, 28b, 28c, 28d, 28e depends on the number of magnetics included in the plurality of magnets 26. In fig. 3, the plurality of magnets 26 includes five magnets, thereby making the plurality of

periods

28a, 28b, 28c, 28d, 28e include two periods. Edge effects prevent the plurality of

periods

28a, 28b, 28c, 28d, 28e from including more than two periods because the sensor 14 cannot reliably measure the magnetic field H near the first end 18 and the second end 20 of the object 12.

With continued reference to fig. 3, the magnets 26 have north and south poles N and S, respectively. The magnets 26 are oriented such that the north poles N and south poles S adjacent to each other have opposite polarities, i.e., each north pole N is adjacent only to one or more south poles S, and each south pole S is adjacent only to one or more north poles N. The opposite polarities of north pole N and south pole S are such that the magnitudes of first vector component V1 and second vector component V2 are sinusoidal with respect to the position of object 12 within the range of positions 22, as shown in fig. 4.

The controller 16 is configured to determine the relative position of the object 12 within an undetermined period of the plurality of

periods

28a, 28b, 28c, 28d, 28e based on the magnitudes of the first vector component V1 and the second vector component V2. The relative position of the object 12 is the position of the object 12 determined during an undetermined period of the plurality of

periods

28a, 28b, 28c, 28d, 28 e. For example, when the plurality of

periods

28a, 28b, 28c, 28d, 28e includes five periods, controller 16 accurately determines the position of object 12 within one of the five periods, but does not determine which of the five periods object 12 is located in. In other words, while the controller 16 may accurately determine the relative position of the object 12 within any given single period, the controller 16 is unable to determine which of the plurality of periods is being measured based on the magnitudes of the first and second vector components V1 and V2.

Accordingly, controller 16 is configured to determine which of the plurality of

periods

28a, 28b, 28c, 28d, 28e object 12 is located in based on the magnitude of third vector component V3. Controller 16 determines the period in which object 12 is located by corresponding the magnitude of third vector component V3 to the period in which object 12 is located. The technique by which the controller determines the period in which the object 12 is located is described in detail below.

Referring now to FIG. 6, in some embodiments, an auxiliary object 30 is secured to object 12. The auxiliary object 30 is fixed to the object 12 such that the auxiliary object 30 has a constant position relative to the object 12 as the object 12 moves within the range of positions 22. For example, in fig. 6, the auxiliary object 30 is fixed to the object 12 such that the auxiliary object 30 is located directly below the object 12. As object 12 moves within the range of positions 22, auxiliary object 30 will continue to be directly beneath object 12. Auxiliary object 30 may be secured to object 12 and positioned relative to object 12 in a manner different from that specifically described herein. The controller 16 is programmed to have a position relative to the object 12 and a position of the auxiliary object 30. When the controller 16 determines the position of the object 12, the controller may also determine the position of the auxiliary object 30 based on the position of the auxiliary object 30 relative to the object 12.

With continued reference to FIG. 6, an exemplary embodiment is shown that includes a clutch actuation member 30 for an automobile (typically a truck) having an automatic mechanical transmission. Automatic mechanical transmissions allow an automotive transmission having a manual transmission gearbox to change gears without requiring a human operator to manually operate a clutch pedal. Automotive transmissions are actuated through automatic clutches by a transmission control module to change gears. The transmission control module is a closed loop control system. In some embodiments, the controller 16 includes a transmission control module.

The clutch actuation member 30 is secured to the clutch positioning rod 32. The clutch positioning lever 32 is actuated in accordance with a signal from the transmission control module to control the position of the vehicle clutch during automatic shifting operation of the automatic mechanical transmission.

The transmission control module requires high accuracy knowledge of the vehicle clutch position in order to smoothly operate the vehicle during gear shifts. The object 12 is secured to the clutch actuating member 30 and extends along the length of the clutch actuating member 30. When the clutch positioning lever is actuated, the object 12 moves within the range of positions 22. The controller 16 communicates the position of the object 12 to the transmission control module. The transmission control module infers the position of the vehicle clutch from knowledge of the fixed distance between the object 12, the clutch actuation member 30 and the vehicle clutch.

Description of the method

FIG. 7 is a flowchart illustrating the detailed operation of method 40 for determining a high accuracy position of object 12. As described above, method 40 occurs when object 12 is within range of position 22.

At step 200, object 12 is moved into range of position 22. Object 12 may move from a position within the range of positions 22 to within the range of positions 22, or may move from a position outside the range of positions 22 to within the range of positions 22.

At step 202, the sensor 14 measures the magnitude of each of the first, second and third vector components V1, V2, V3.

At step 204, the controller 16 determines the relative position of the object 12 within an undetermined period of the plurality of

periods

28a, 28b, 28c, 28d, 28 e. The relative position is expressed as a position parameter. In one embodiment, the controller 16 does so by determining a position parameter having a tangent equal to the quotient of the magnitude of the first vector component V1 and the magnitude of the second vector component V2. The position parameter is a value between-pi/2 radians and pi/2 radians (i.e., -90 degrees and 90 degrees).

Fig. 5 is a graph having a horizontal axis, a vertical magnetic field axis, and a vertical axis. The position axis corresponds to the position of object 12 within the range of positions 22. The leftmost value on the position axis corresponds to object 12 being located within position 22 such that sensor 14 is closest to first end 18 of object 12. Increasing the value of the position axis, i.e., moving toward the right of the position axis, corresponds to object 12 being located within a range of positions 22 such that sensor 14 is closer to second end 20 of object 12, wherein the rightmost value on the position axis corresponds to object 12 being located within a range of positions 22 such that sensor 14 is closest to second end 20 of object 12.

The magnetic field axis corresponds to the magnitude of the third vector component V3 measured by the sensor 14 and communicated to the controller 16 at each position along the position axis. In FIG. 5, the magnitude of third vector component V3 continuously increases as object 12 moves across the range of positions 22 such that sensor 14 measures the magnitude of third vector component V3 from near first end 18 of object 12 to near second end 20 of object 12.

The angular axis corresponds to the value of the position parameter that controller 16 calculated at step 204 for each position of object 12 along the position axis. Since the position parameter is a function of the amplitudes of the first vector component V1 and the second vector component V2, the value of the position parameter is a periodic function having the same period as the sinusoid of the amplitudes of the first vector component V1 and the second vector component V2. Thus, each period of the value of the position parameter corresponds to a period of the plurality of

periods

28a, 28b, 28c, 28d, 28 e. Since the position parameter has the same value θ 1, θ 2 in each of the plurality of

periods

28a, 28b, 28c, 28d, 28e, the undetermined period of the plurality of

periods

28a, 28b, 28c, 28d, 28e is indeterminate. Thus, determining the position parameters allows for a high accuracy in determining the relative position of the object 12 within an undetermined period of the plurality of

periods

28a, 28b, 28c, 28d, 28 e.

In some embodiments, the controller 16 determines the relative position by retrieving a position parameter from a position parameter lookup table. The position parameter lookup table is a portion of memory accessible by the controller 16 having recorded values of position values corresponding to the magnitudes of the first vector component V1 and the second vector component V2. In other embodiments, the controller 16 determines the relative position by calculating a position parameter based on the magnitude of the first vector component V1 and the second vector component V2. In situations where the controller 16 has limited processing power, it may be advantageous to retrieve the location parameters from a location parameter look-up table. In the case of a controller 16 with limited memory, it is advantageous to calculate the position parameter from the magnitudes of the first vector component V1 and the second vector component V2.

At step 206, controller 16 determines the period in which object 12 is located. With continued reference to FIG. 5, since the magnitude of third vector component V3 is a monotonic function of the position of object 12 within range of positions 22, the magnitude of third vector component V3 is unique for each position of object 12 within range of positions 22. Thus, each of the plurality of

periods

28a, 28b, 28c, 28d, 28e has a respective magnitude range of the third vector component V3 corresponding thereto. In fig. 5, the plurality of

periods

28a, 28b, 28c, 28d, 28e includes 2.5 periods. The magnitude of the third vector component V3 has a different magnitude range corresponding to each of the plurality of

periods

28a, 28b, 28c, 28d, 28 e. In some embodiments, controller 16 determines the period in which object 12 is located by retrieving the period corresponding to the magnitude of third vector component V3 from a period lookup table. In other embodiments, controller 16 determines the period in which object 12 is located by calculating the period in which object 12 is located based on the magnitude of third vector component V3.

FIG. 5 illustrates an exemplary position P1, a first exemplary position parameter θ 1, a second exemplary position parameter θ 2, and an exemplary third vector component HP 1. The exemplary position P1 is within the first period 28 a. When the object 12 is located at the exemplary position P1, a first exemplary position parameter θ 1 and a second exemplary position parameter θ 2 are determined. The first exemplary position parameter θ 1 is within the first period 28 a. The second example position parameter θ 2 has a value equal to the first example position parameter θ 1 and is within the second period 28 b. Exemplary third vector component HP1 is the magnitude of third vector component V3 measured when object 12 is located at exemplary position P1.

At step 208, controller 16 calculates an absolute position of object 12 based on the relative position and the period. The absolute position of object 12 is a high accuracy determination of the position of object 12 within a period of the plurality of

periods

28a, 28b, 28c, 28d, 28e in which object 12 is located. Controller 16 determines the absolute position of object 12 by comparing the determination of the relative position of object 12 in step 204 to the determination of the period in which controller 16 determines that object 12 is located in step 206.

The present invention is described herein in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the present invention are possible in light of the above teachings. The invention may be practiced otherwise than as specifically described within the scope of the appended claims.

Claims

1. A system for determining a location, the system comprising:

an object configured to generate a magnetic field having a first vector component, a second vector component, and a third vector component, and wherein the first, second, and third vector components are mutually orthogonal;

a sensor configured to measure a magnitude of each of the first, second, and third vector components when the object is within a range of positions; and

a controller connected to the sensor and configured to determine a relative position of the object within an undetermined period of a plurality of periods based on the magnitude of the first vector component and the magnitude of the second vector component to determine a period of the plurality of periods in which the object is located based on the magnitude of the third vector component, and wherein the controller determines an absolute position of the object based on the relative position of the object and the period in which the object is located;

wherein the magnitude of the first vector component and the magnitude of the second vector component are periodic functions having a phase difference as the object moves across the range of positions, and the magnitude of the third vector component is unique for each possible position of the object within the range of positions.

2. The system of claim 1, wherein the controller is further configured to determine the period in which the object is located by retrieving a period from a lookup table that corresponds to a magnitude of the third vector component.

3. The system of claim 1, wherein the controller is further configured to determine the period in which the object is located by calculating the period from the magnitude of the third vector component.

4. The system of claim 1, wherein the object is further configured to generate the magnetic field such that the third vector component has a substantially constant slope with respect to a position of the object within the range of positions.

5. The system of claim 4, wherein the slope of the third vector component is further defined as monotonic.

6. The system of claim 1, wherein the object is further defined as a single magnet configured to generate the magnetic field.

7. The system of claim 1, wherein the object comprises a plurality of magnets configured to together generate the magnetic field.

8. The system of claim 1, wherein the controller is further configured to determine the relative position of the object by retrieving a position parameter from a lookup table having a tangent equal to a quotient of a magnitude of the first vector component and a magnitude of the second vector component.

9. The system of claim 1, wherein the controller is further configured to determine the relative position of the object by calculating a position parameter having a tangent equal to a quotient of a magnitude of the first vector component and a magnitude of the second vector component.

10. The system of claim 1, wherein the object is further configured to move along a predetermined path within the range of positions.

11. The system of claim 10, wherein the magnitude of each of the first, second, and third vector components measured by the sensor is configured to change as the object moves along the predetermined path within the range of positions.

12. The system of claim 1, wherein the controller is further configured to determine the relative position of the object based only on a magnitude of the first vector component and a magnitude of the second vector component.

13. The system of claim 1, wherein the controller is further configured to determine the period in which the object is located based only on a magnitude of the third vector component.

14. The system of claim 1, wherein the sensor is further defined as a magnetometer.

15. The system of claim 1, wherein the controller is further configured to determine a position of an auxiliary object based on the absolute position of the object.

16. The system of claim 1, wherein the object is secured to a clutch positioning component of an automatic mechanical transmission.

17. A method of operating a system for determining position, the system comprising an object, a sensor, and a controller connected to the sensor, and the object being configured to move within a range of positions and configured to provide a magnetic field having a first vector component, a second vector component, and a third vector component, wherein the first, second, and third vector components are mutually orthogonal, the method comprising the steps of:

moving the object within the range of positions;

measuring with the sensor a magnitude of each of the first, second and third vector components when the object is within the range of positions;

determining, with the controller, a relative position of the object over an undetermined period of a plurality of periods based on the magnitude of the first vector component and the magnitude of the second vector component;

determining, with the controller, a period of the plurality of periods in which the object is located based on the magnitude of the third vector component; and

determining, with the controller, an absolute position of the object based on the relative position of the object and the period in which the object is located;

wherein the magnitude of the first vector component and the magnitude of the second vector component are periodic functions and the magnitude of the third vector component is unique for each possible position of the object within the range of positions as the object moves across the range of positions.

18. The method of claim 17 wherein the step of determining with the controller the period in which the object is located is further defined as retrieving with the controller from a look-up table a period corresponding to the magnitude of the third vector component.

19. The method as set forth in claim 17 wherein the step of determining with the controller the period in which the object is located is further defined as calculating with the controller the period as a function of the magnitude of the third vector component.

20. The method as set forth in claim 17 wherein the step of determining with the controller the relative position of the object is further defined as retrieving with the controller from a look-up table a position parameter having a tangent equal to the quotient of the magnitude of the first vector component and the magnitude of the second vector component.

21. The method as set forth in claim 17 wherein the step of determining the relative position of the object with the controller is further defined as calculating with the controller a position parameter having a tangent equal to the quotient of the magnitude of the first vector component and the magnitude of the second vector component.

22. An object for use in position sensing, the object comprising a length and being configured to move linearly along a single axis over a range of positions, the object comprising one or more magnets and being configured to generate a magnetic field having a first vector component, a second vector component and a third vector component, wherein the first, second and third vector components are mutually orthogonal, and wherein the magnets are oriented such that north and south poles adjacent to each other have opposite polarities, such that the magnitude of the first vector component and the magnitude of the second vector component each vary periodically along the length of the object, and wherein the magnitude of the third vector component is monotonic along the length of the object.

23. The object of claim 22, wherein the magnitude of the third vector component is monotonic such that the magnitude of the third vector component is unique for each position along the length of the object.

24. The object of claim 22, wherein the magnitude of the first vector component and the magnitude of the second vector component each vary periodically along the length of the object such that the relative position of the object can be determined over an undetermined period of a plurality of periods based on the magnitude of the first vector component and the magnitude of the second vector component.

25. The object according to claim 24, wherein the magnitude of the third vector component is monotonic along the length of the object such that a period of the plurality of periods in which the object is located can be determined based on the magnitude of the third vector component.

26. The object of claim 22, wherein the object further comprises a cylindrical configuration having a first end and a second end, and the length is defined between the first end and the second end.

27. The object of claim 22, wherein:

the first vector component extends radially from the object;

the second vector component extends longitudinally through the object; and is

The third vector component extends radially from the object and is orthogonal to both the first vector component and the second vector component.

28. The object according to claim 22, wherein the object is configured to be secured to a clutch positioning component of an automated mechanical transmission.